This better have been an accident.
It likely is. Their quality control has been trash when it comes to rocket/missile production. This isn’t the first errant launch, one also landed short inside of Russia this morning. Before the most recent Ukraine invasion, no one hated Russia more than Poland. Allowing Russia to bulldoze Ukraine and sit on Poland’s border would have definitely led to a larger conflict. This is the usual stupidity on Russia’s part. Poland didn’t immediately shoot back so I don’t think this is going to spin out of control. Moves will be made, over the next couple of months to make Russia regret this though.